Opt Quant Electron (2013) 45:329–342 DOI 10.1007/s11082-012-9646-0 Tailored design of WDM filters in BCB embedded PhC membranes Stefania Malaguti · Gaetano Bellanca · Luisa Ottaviano · Kresten Yvind · Sylvain Combrié · Alfredo De Rossi · Stefano Trillo Received: 31 July 2012 / Accepted: 11 December 2012 / Published online: 21 December 2012 © Springer Science+Business Media New York 2012 Abstract We propose a design strategy for wavelength division multiplexing (WDM) filters in BCB embedded photonic crystal membranes. Due to the weaker vertical confinement determined by the material embedding the whole structure, accurate tailoring of the resonant cavity and of both bus and drop waveguides is necessary, in order to guarantee the required performance of the filter for WDM applications. Keywords Photonic crystals · Photonic crystal cavities · Photonic crystal filters 1 Introduction Multi-channel drop filters are fundamental components for wavelength division multiplexing (WDM) and dense wavelength division multiplexing (DWDM) applications. These devices are usually realized through a cascade of different sections (Channel drop filters—CDFs) operating on a single wavelength of the WDM frame. Accurate wavelength selectivity, high drop efficiency and low insertion loss are the most important parameters of these compo- nents. Minimization of the channel spacing and device miniaturization are mandatory to guarantee an efficient use of the available spectral resources and to realize high-density inte- grated optical circuits. Photonic Crystal technology, with its capability of controlling the light propagation on a wavelength scale, has been repeatedly proposed as a suitable platform S. Malaguti · G. Bellanca (B )· S. Trillo Department of Engineering, University of Ferrara, Ferrara, Italy e-mail: gaetano.bellanca@unife.it S. Malaguti e-mail: stefania.malaguti@unife.it L. Ottaviano · K. Yvind DTU Fotonik, Lyngby, Denmark S. Combrié · A. De Rossi Thales Research and Technology, Palaiseau, France 123